Repair versus replacement of mitral valves in cases of severe rheumatic mitral stenosis: mid-term clinical outcomes

Mitral Valve Repair vs. Replacement by Different Etiologies - A Nationwide Population-Based Cohort Study

BACKGROUND

When mitral valve (MV) surgery is indicated, repair is preferred over replacement; however, this preference is not supported by evidence from clinical trials. Furthermore, the benefits of MV repair may not be universal for all etiologies of MV disease.

METHODS AND RESULTS

This study identified a total of 18,428 patients who underwent MV repair (n=4,817) or MV replacement (n=13,611) during 2001-2018 from Taiwan's National Health Insurance Research Database. These patients were classified into 4 etiologies: infective endocarditis (IE, n=2,678), rheumatic heart disease (RHD, n=4,524), ischemic mitral regurgitation (IMR, n=3,893), and degenerative mitral regurgitation (DMR, n=7,333). After propensity matching, all-cause mortality during follow-up was lower among patients receiving MV repair than among patients receiving MV replacement in the IE, IMR, and DMR groups (hazard ratio [HR]=0.72, 95% confidence interval [CI]: 0.55-0.93; HR=0.82, 95% CI: 0.73-0.92; and HR 0.73, 95% CI: 0.64-0.84, respectively). However, in the RHD group, the MV reoperation rate was higher after MV repair than after MV replacement (subdistribution HR=1.91, 95% CI: 1.02-3.55).

CONCLUSIONS

In comparison with MV replacement, MV repair was associated with a lower late mortality in patients with IE, IMR, and DMR, and a higher risk of reoperation in patients with RHD.

Comparison of Repair vs Replacement in Calcific and Rheumatic Mitral Disease

BACKGROUND

The benefit of repair over replacement of rheumatic or calcified mitral valve (MV) is debatable.

METHODS

Patients who underwent MV repair or replacement for rheumatic or calcified MV disease between 2006 and 2020 were identified in the Polish National Registry of Cardiac Surgery Procedures. Patients who underwent additional procedures other than coronary artery bypass grafting or tricuspid valve surgery, as well as redo or emergency cases, were excluded. The long-term survival was verified based on National Health Fund registry data. The survival was compared between MV repair and replacement in the whole cohort and after propensity score matching.

RESULTS

We included 4338 patients: 1859 (43%) with pure mitral regurgitation and 2479 (57%) with mitral stenosis. MV was repaired in 543 patients (29%) with pure regurgitation and 126 (5.1%) with stenosis (P < .001). In total, 984 (23%) patients underwent concomitant coronary artery bypass grafting and 1358 (32%) tricuspid valve surgery. MV repair improved survival (hazard ratio 0.81; 95% CI 0.68-0.97; P = .022) in patients with no mitral stenosis, and had no effect in mitral stenosis (hazard ratio 1.17; 95% CI 0.85-1.59; P = .332). The results were confirmed in propensity-matched cohorts. The freedom from MV reoperation at 10 years was 95.5% ± 1.2% after repair and 96.0% ± 0.7% after MV replacement (P = .416) in the absence of stenosis and 91.8% ± 3.4% after repair vs 95.9% ± 0.5% after replacement in patients with mitral stenosis (P = .065).

CONCLUSIONS

Repair of rheumatic/calcified mitral valve should be a preferred option in patients with no mitral stenosis, but confers no benefit if mitral stenosis is present.

Predictors of Outcome in Patients with Pulmonary Hypertension Undergoing Mitral and Tricuspid Valve Surgery

Background and Objectives: Pulmonary hypertension (PH) secondary to left-sided valvular heart disease is associated with poor cardiac surgical outcome compared with patients without PH. Our objective was to investigate the prognostic factors of surgical outcome in patients with PH undergoing mitral valve (MV) and tricuspid valve (TV) surgery, in order to risk stratify their management. Materials and Methods: This is a retrospective observational study on patients with PH who underwent MV and TV surgery from 2011 to 2019. The primary outcome was all-cause mortality. The secondary outcomes were post-op respiratory and renal complications, length of intensive care unit stay and length of hospital stay. Results: Seventy-six patients were included in this study. The all-cause mortality was 13% (n = 10), with mean survival of 92.6 months. Among the patients, 9.2% (n = 7) had post-op renal failure requiring renal replacement therapy and 6.6% (n = 5) had post-op respiratory failure requiring intubation. Univariate analysis demonstrated that pre-operative left ventricular ejection fraction (LVEF), peak systolic tissue velocity at the tricuspid annulus (S') and etiology of MV disease were associated with respiratory and renal failure. Tricuspid annular plane systolic excursion (TAPSE) was associated with respiratory failure only. S', type of operation, LVEF, urgency of surgery, and etiology of MV disease were found to be predictive of mortality. After excluding redo mitral surgery, all statistically significant findings remain unchanged, with the addition of right ventricular (RV) size being associated with respiratory failure. In the subgroup analysis of routine cases (n = 56), patients with primary mitral regurgitation who underwent mitral valve repair had better survival outcome. Conclusions: Urgency of surgery, etiology of MV disease, type of operation (replacement or repair), S' and pre-op LVEF are prognostic indicators in this small cohort of patients with PH undergoing MV and TV surgery. A larger prospective study is warranted to validate our findings.

Short and mid-term effects of modified release technique in rheumatic mitral valve repair

OBJECTIVE

Repair or replacement remains debatable in rheumatic heart disease. To regain optimal mean transvalvular pressure gradients and end-diastolic peak flow velocity, the modified release technique combined peeling in the anterior leaflet and separated the shortened chordal. In the end, the short and mid-term outcomes of the modified release technique were evaluated.

METHODS

We retrospectively analyzed a series of 128 patients with rheumatic mitral stenosis, from January 2018 to July 2021 in our center. All patients undergoing mitral valve repair were using the modified release technique. The effect of mitral valve repair was evaluated by intraoperative transesophageal echocardiography and postoperative transthoracic echocardiography.

RESULTS

All the 128 patients successfully repaired the mitral valve. The intraoperative transesophageal echocardiography showed trivial or mild regurgitation. The aortic valve was repaired without obvious regurgitation in 12 cases, 5 cases received an aortic valve replacement, 89 cases underwent tricuspid annuloplasty. There were no blood transfusions in most patients, no deaths nor complications during peri-operation, also, no deaths and adverse events were observed during the follow-up period from 3 to 42 months. During the follow-up, 122 cases had no mitral valve regurgitation and 2 cases of moderate regurgitation, 4 cases of mild to moderate regurgitation. The mean peak flow velocity was 1.2 ± 0.3 m / s, no new-onset stenosis occurred.

CONCLUSION

Modified release technique is safe and feasible. Its durability is acceptable in the short and mid-term, with no new-onset stenosis during the follow-up.

Mechanical versus Bioprosthetic Aortic Valve Replacement in Middle-Aged Adults: A Systematic Review and Meta-Analysis

BACKGROUND

Mechanical prostheses and bioprosthetic prostheses have their own advantages and disadvantages. Mechanical ones are recommended for younger patients (<50 years old), and bioprosthetic ones are recommended for older patients (>70 years old). There is still debate regarding which kind of prosthesis is better for middle-aged patients (50 to 70 years old) receiving aortic valve replacement (AVR). To solve this problem, we conducted this meta-analysis. Given that only one randomized controlled trial (RCT) study was included, we conducted a subgroup analysis of RCT and propensity score matching (PSM) retrospective studies to reduce the bias.

METHODS

We systematically searched articles related to clinical outcomes of mechanical and bioprosthetic prostheses in middle-aged patients receiving AVR in the PubMed, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases. The published date was up to 1 October 2022. Studies were excluded if not only middle-aged patients were included, or if they lacked direct comparisons between mechanical and bioprosthetic prostheses.

RESULTS

In total, 22 studies with 32,298 patients were included in the final analysis. The results show that patients aged between 50 and 70 receiving AVR with mechanical prostheses achieved better long-term survival and fewer reoperations and valve-related events but suffered more with bleeding events. No significant difference could be found in terms of early mortality and long-term cardiac death. The same results could be observed in the subgroup analysis of RCT and PSM retrospective studies.

CONCLUSION

Both mechanical and bioprosthetic prostheses are beneficial to middle-aged patients undertaking AVR procedures. However, mechanical prostheses show better clinical outcomes in long-term survival and comorbidities. Individual recommendation is still necessary.

A Novel Rheumatic Mitral Valve Disease Model with Ex Vivo Hemodynamic and Biomechanical Validation

PURPOSE

Rheumatic heart disease is a major cause of mitral valve (MV) dysfunction, particularly in disadvantaged areas and developing countries. There lacks a critical understanding of the disease biomechanics, and as such, the purpose of this study was to generate the first ex vivo porcine model of rheumatic MV disease by simulating the human pathophysiology and hemodynamics.

METHODS

Healthy porcine valves were altered with heat treatment, commissural suturing, and cyanoacrylate tissue coating, all of which approximate the pathology of leaflet stiffening and thickening as well as commissural fusion. Hemodynamic data, echocardiography, and high-speed videography were collected in a paired manner for control and model valves (n = 4) in an ex vivo left heart simulator. Valve leaflets were characterized in an Instron tensile testing machine to understand the mechanical changes of the model (n = 18).

RESULTS

The model showed significant differences indicative of rheumatic disease: increased regurgitant fractions (p < 0.001), reduced effective orifice areas (p < 0.001), augmented transmitral mean gradients (p < 0.001), and increased leaflet stiffness (p = 0.025).

CONCLUSION

This work represents the creation of the first ex vivo model of rheumatic MV disease, bearing close similarity to the human pathophysiology and hemodynamics, and it will be used to extensively study both established and new treatment techniques, benefitting the millions of affected victims.

Altered Expression of Transfer-RNA-Derived Small RNAs in Human With Rheumatic Heart Disease

Rheumatic heart disease (RHD) remains a severe public health problem in developing countries. Atrial fibrillation (AF) is a medical complication of RHD. Although the understanding of disease pathogenesis has advanced in recent years, the key questions need to be addressed. Transfer RNA–derived small RNAs (tsRNAs) are a novel type of short non-coding RNAs with potential regulatory functions in various physiological and pathological processes. The present study used tsRNAs sequencing to investigate the relationship between RHD and atrial fibrillation (AF). Three paired cardiac papillary muscles were taken from six rheumatic RHD patients with AF (3 cases) or without AF (3 cases) from January 2016 to January 2017 in Xiangya Hospital, Central South University. A total of 219 precisely matched tsRNAs were identified, and 77 tsRNAs (fold change > 2.0 and P < 0.05) were differently changed. Three tsRNAs (AS-tDR-001269, AS-tDR-001363, AS-tDR-006049) were randomly selected and confirmed by qRT-PCR. The results of qRT-PCR were consistent with tsRNAs sequencing, suggesting the tsRNAs sequencing was reliable. Subsequently, we predicted the target mRNAs of the three tsRNAs. Moreover, we verified the functions of tsRNAs targeting mRNAs in vitro. Finally, bioinformatics analysis indicated that the target genes were abundant in regulation of transcription, DNA binding, intracellular. Most of the genes were predicted to interplay with cytokine-cytokine receptor by KEGG analysis. Our findings uncover the pathological process of AF in RHD through tsRNAs sequencing. This research provides a new perspective for future research on elucidating the mechanism of AF in RHD and offers potential new candidates for the treatment and diagnosis.

Clinico-pathological classification of rheumatic mitral valve damage and surgical strategy

Background

There is a lack of established pathological indications for rheumatic valve repair. Therefore, we summarized the pathological classifications of rheumatic heart diseases and their correlations with the surgical strategies.

Methods

This observational study enrolled patients with rheumatic heart diseases who underwent mitral valve repair (MVP) or replacement at our centre between January 2017 and January 2019. Mitral leaflet, mitral commissural, and sub-valvular apparatus were classified into three grades from mild to severe, according to their degree of pathological damage. Based on certain principles and the grade of mitral leaflet, mitral commissural, and sub-valvular apparatus damage, three pathological types were identified (types I to III), based on which all patients were classified. The features of each pathological type were summarised. Differences between the three pathological types were analysed using chi-square test of tendency. These data were used to propose a clinico-pathological classification of rheumatic mitral valve damage in Chinese patients.

Results

Of 398 patients, 284 (70%) underwent MVP for rheumatic mitral valve diseases. There were 58 type I (15%) patients in the study, all of whom underwent repair (repair rate, 100%). Preoperative moderate-to-severe regurgitation with mild pathological lesions was observed in 64% of these patients. In 260 type II (65%) patients, the repair rate was 76% (197/260); preoperative moderate-to-severe stenosis was observed in 88% of these patients. In 80 type III (20%) patients, the repair rate was 36% (29/80); the preoperative rates of extremely severe stenosis and moderate-to-severe regurgitation in these patients were 50% and 40%, respectively. Several preoperative parameters show the change in trend with the increase in the pathological classification severity.

Conclusions

Our clinico-pathological classification of rheumatic mitral valve damage is applicable to MVP. Considering that the classification principles are based on the possibility of mitral repair, it provides a phased and achievable target ratio for MVP and a principle of screening patients who should undergo rheumatic MVP.

Clinical outcomes following surgical mitral valve repair or replacement in patients with rheumatic heart disease: a meta-analysis

Background

The clinical outcome of mitral valve repair (MVP) is considerably more favorable than that of mitral valve replacement (MVR) in patients with degenerative mitral disease. However, rheumatic heart disease (RHD) is still the predominant cause of mitral valve surgery in developing countries and the advantages of MVP in RHD have still not been definitely proven. The aim of this meta-analysis was thus to evaluate the suitability of MVP in patients with RHD. Considering the difference between mechanical and biological valves, we distinguished them from each other and compared them with MVP individually.

Methods

A comparison of clinical outcomes of MVP and MVR in patients with RHD was performed based on clinical trial data. Relevant articles published from January 1, 1990 until March 1, 2020 were identified in Pubmed, Cochrane Library, and China National Knowledge Infrastructure database (CNKI). Studies that lacked direct comparisons between MVP and MVR were excluded.

Results

A total of 16 studies with 8659 patients were included in the analysis. The MVP group displayed lower early and long-term mortality, and fewer valve-related events and major adverse events. However, this patient group required more reoperations compared with the MVR group. Similar results were observed after distinguishing between mechanical and bioprosthetic valves to compare MVP with MVR (mech-valves), but no statistically significant difference was identified in the reoperation rate between MVP and MVR (bio-valves). MVP was further associated with increased risk of mitral reoperation in patients undergoing concomitant aortic valve replacement (AVR) surgery but without any improved early and long-term survival.

Conclusions

MVP and MVR are beneficial for patients with RHD. For skilled surgeons, MVP can be performed for some suitable patients with RHD and is preferred for elderly patients or patients with contraindications of anticoagulation. However, MVR is more appropriate when concomitant AVR is needed.